Methods of and devices for implementing and executing policy rules on a per application basis in a telecommunications system

ABSTRACT

Implementation of an application rule for an application to be accessed by a User Equipment, UE, in a user session in a Service Based Architecture, SBA, domain in a core network of a telecommunications system is disclosed. The SBA, among others, comprises a Policy Control Function, PCF (6), an Application Function, AF (5), and a Session Management Function, SMF (9). The method comprising the steps of receiving, by the PCF (6), an application rule comprising an AF Identifier, AF-ID, identifying the application rule, an Application Identifier, App-ID, identifying the application, and at least one service requirement for processing the application in the SBA domain. The PCF (6) instructing the SMF (9) to execute the at least one service requirement to all present and future user sessions pertaining to the respective application. Complementary methods of supporting the execution of the application rule and devices are also presented.

CROSS REFERENCE TO RELATED APPLICATION(S)

This application is a divisional of U.S. patent application Ser. No.17/287,139, filed Apr. 21, 2021, which is a 35 U.S.C. § 371 NationalPhase Entry Application from PCT/EP2018/083328, filed Dec. 3, 2018,designating the United States, and also claims the benefit of EuropeanApplication No. 18382758.3, filed Oct. 25, 2018, the disclosures ofwhich are incorporated herein by reference in their entirety.

TECHNICAL FIELD

The present disclosure generally relates to the field oftelecommunications systems, and more specifically to the execution ofpolicy rules relating to an application in a Service Based Architecture,SBA, domain in a core network of a telecommunications system, such as aFifth Generation, 5G, telecommunication network.

BACKGROUND

The Fifth Generation, 5G, telecommunications core network architectureis an example of a Service Based Architecture, SBA, in which NetworkFunctions, NF, provide one or multiple services to entities requiringtelecommunications services from a particular NF. In turn, an NF mayalso request telecommunications services from another NF, for example.The NFs of the Core Network, CN, are self-contained functionalities thatcan be modified and updated in an isolated manner, i.e. withoutaffecting other NFs.

The Application Function, AF, is an element offering applications thatrequire policy and charging control of traffic plane resources, andinteracts with the Third Generation Partnership Project, 3GPP, CoreNetwork in order to provide, for example, services to support:

-   -   application influence on traffic routing,    -   interaction with the policy framework for policy control, and    -   access of the Network Exposure Function, NEF.

Based on operator deployment, for example, AFs that are considered to betrusted may be allowed to interact directly with other relevant NFs,such as a Policy Control Function, PCF, a Session Management Function,SMF, and a User Plane Function, UPF. AFs that are not allowed by anoperator to directly access other NFs shall use the external exposureframework, via the NEF, to interact with other relevant NetworkFunctions.

The Policy Control Function, PCF, includes, among others, the followingfunctionality:

-   -   support for unified policy framework, to govern network        behaviour,    -   providing policy rules to Control Plane Function(s), CPFs, for        enforcing thereof, and    -   access of subscription information relevant for policy decisions        in a Unified Data Repository, UDR.

The Session Management function, SMF, supports different functionality,such as session establishment, modification and release, and policyrelated functionalities like termination of interfaces towards policycontrol functions, charging data collection, support of charginginterfaces and control and coordination of charging data collection atthe UPF.

The User Plane function, UPF, supports handling of user plane traffic,including packet inspection, packet routing and packet forwarding,traffic usage reporting, and Quality of Service, QoS, handling for theuser plane, such as Uplink/Downlink, UL/DL, rate enforcement, forexample.

Unified Data Management, UDM, supports the Authentication CredentialRepository and Processing Function, ARPF, and stores the long-termsecurity credentials used in the Authentication and Key-Agreement, AKA,procedures in the 3GPP 5G Architecture.

The 5G system architecture allows the UDM, PCF and NEF to store data inthe UDR, including subscription data and policy data, structured datafor exposure and application data including Packet Flow Descriptions,PFDs, for application detection by the NEF.

Content providers may be interested in network services applying aspecific data handling, such as a high QoS or charging treatment fortheir applications traffic, for example. To achieve this, contentproviders usually conclude a Service Level Agreement, SLA, with one orseveral network operators, relating to the level of service to beprovided for a particular application.

The current 3GPP standards specify that policy and charging control hasto be applied on a per user or per Protocol Data Unit, PDU, sessionbasis. There is no mechanism in the policy and charging controlframework which allows a content provider to request a certain QoS orcharging treatment on a per application basis for all user sessions, forexample for a social media type application or the like, having arelatively huge amount of subscribers.

The existing northbound Application Programming Interfaces, APIs,between the AF and the NEF allow the content provider to request acertain QoS, for example a high QoS, or special charging, such assponsored data, for a certain application but only on a per individualuser session basis. This holds, for example, for the northbound API for“Setting up an AS session with required QoS” or “Changing the chargeableparty at session set up or during the session”, currently defined in the3GPP standards.

Accordingly, there is a need for implementing, in an SBA, servicefunctionality relating to the processing of data and charging treatmentfor traffic on an application basis.

SUMMARY

In a first aspect of the present disclosure, there is presented a methodof implementing an application rule for an application to be accessed bya User Equipment, UE, in a user session in a Service Based Architecture,SBA, domain in a core network of a telecommunications system, the SBAamong others comprising a Policy Control Function, PCF, an ApplicationFunction, AF, a User Plane Function, UPF and a Session ManagementFunction, SMF.

The method comprises the steps of: receiving, by the PCF, an applicationrule comprising an AF Identifier, AF-ID, identifying the respectiveapplication rule, an Application Identifier, App-ID, identifying therespective application, and at least one service requirement forservicing the respective application in the SBA domain, the applicationrule being different from existing Policy Charging and Control, PCC,rules and having higher precedence than existing per session PCC rules,and instructing, by the PCF, the SMF to execute the at least one servicerequirement to all present and future user sessions pertaining to therespective application.

In its first aspect, the present disclosure provides a special set ofpolicy rules to be implemented in a PCF for handling data in an SBAtelecommunications system on a per application basis. A respectivepolicy or application rule is identified by its AF-ID, and theapplication to which an application rule pertains is identified by theApp-ID, whereas the service or services to be provided are defined bythe at least one service requirement.

In order to ensure uniform treatment or servicing of a particularapplication in the telecommunications system, the PCF is arranged toinstruct the SMF to execute the at least one service requirement to allpresent and future user sessions pertaining to a respective application.

In a 5G SBA, for example, the PCF may install application rules in anSMF by means of triggering an Nsmf HTTP POST message to the SMF,including AF-ID, App-ID and a respective service requirement. Note theseapplication rules are different to the existing Policy Charging andControl, PCC, rules as the application rules do not apply to a specificuser session, but instead they apply to any existing or present andfuture user session.

Alternatively, the PCF could identify all the existing user sessionswhich would require a service modification and trigger PCC rulemodification on a per user session basis, but this would result in a lotof messages which would significantly increase signalling in thenetwork, in particular for applications that are used on a wide scale,such as social media type applications.

The solution according to the present disclosure enables flexibleservicing of data exchanged in an SBA domain for one or severalapplications of a particular content provider or different contentproviders, simply by implementing a respective application rule in thePCF.

Although in a particular application rule all the service requirementsmay be specified that are available in an SBA domain for data or traffichandling on an individual user or session basis, in an example of thepresent disclosure, the application rule comprises at least one of aspecific Quality of Service, QoS, handling for user sessions pertainingto the application to be accessed by the UE, and/or a specific chargingprofile for user sessions pertaining to the application to be accessedby the UE.

That is, data exchanged between a respective application of a contentprovider and all the UE in a system accessing a particular applicationfor which an application rule is implemented and enforced, receive arequired QoS specified in the respective application rule, for examplebetter than a default QoS, and/or are charged against a particularagreed, for example reduced, tariff or fee.

It may be understood by the skilled person that when PCF instructs SMFto execute at least one service requirement to all existing and futureuser sessions using that application, the service requirement might beexecuted at SMF but in some cases it may be needed to be executed atUPF. For example, QoS Bandwidth limitation is a service requirement thatSMF cannot perform itself, and hence the SMF may need to instruct UPF todo so through a new N4 procedure, per application. The step ofinstructing, therefore may additionally comprise the step ofinstructing, by the SMF, the UPF to execute the application ruleprovided to the SMF by the PCF.

According to an embodiment, wherein the SBA domain comprises a UnifiedData Repository, UDR, the method further comprises the steps of:transmitting, by the PCF, a received application rule to the UDR, forstoring in the UDR as application rule, in particular in associationwith a respective user session policy rule, and receiving, by the PCF,from the UDR, a message acknowledging the storage of the applicationrule.

An application rule may be stored in the UDR in association withexisting policy rules relating to user sessions, i.e. Protocol DataUnit, PDU, sessions and respective application data. In the case of anapplication rule specifying a particular QoS and/or charging treatmentother than specified for an individual or per user session, for example,this application rule is stored in association with the respective peruser session QoS and/or charging policy rule. Those skilled in the artwill appreciate that for a respective application several, differentapplication rules may be stored.

For applying a particular application rule at initiation of a PDUsession by a UE, a further embodiment of the present disclosurecomprises the steps of: receiving, by the PCF, from the SMF, a requestfor retrieving at least one policy rule for the PDU session; retrieving,by the PCF, from the UDR, the or each stored policy rule including atleast one application rule for the PDU session, and providing, by thePCF, the retrieved policy and application rules to the SMF.

It is assumed that application rules, if available, have a higherprecedence than existing per user session or PDU session policy rules.However, in accordance with the present disclosure, a precedenceparameter may be implemented in an application rule, for example,indicating a particular priority or preference level of the applicationrule over other policy rules pertaining to a user session.

According to an embodiment, the PCF may receive an application rule froman Application Function, AF, handling the application that requires aspecific treatment. However, according to another exemplary embodiment,the PCF may also receive an application rule from a network operator.

In a second aspect of the present disclosure, there is presented amethod of supporting the execution of an application rule for anapplication to be accessed by a User Equipment, UE, in a user session ina Service Based Architecture, SBA, domain in a core network of atelecommunications system, the SBA among other comprising a PolicyControl Function, PCF, an Application Function, AF, a User PlaneFunction, and a Session Management Function, SMF.

The method according to the second aspect comprises the steps of:receiving, by the SMF, an instruction from the PCF, instructing the SMFto execute a desired application rule to all present and future usersessions pertaining to the application, the desired application rulebeing different from existing Policy Charging and Control, PCC, rulesand having higher precedence than existing per session PCC rules;identifying, by the SMF, user sessions to which the desired applicationrule is applicable, and executing, by the SMF, the desired applicationrule to the identified user sessions.

The SMF identifies the active user sessions which require a servicemodification, such as a QoS modification and/or a new charging handling,and applies the new service requirement or requirements for each of therespective sessions. The SMF may respond back to the PCF, for examplewith an Nsmf 200 OK successful response in the case of a 5G SBA.

According to an embodiment, the received instruction comprises an AFIdentifier, AF-ID, an Application Identifier, App-ID, and at least oneservice requirement for processing the application in the SBA domain,wherein the identified user sessions are identified on the basis of theAF-ID and the App-ID.

In a third aspect of the present disclosure, there is presented a methodof supporting the execution of an application to be accessed by a UserEquipment, UE, in a user session in a Service Based Architecture, SBA,domain in a core network of a telecommunications system, the SBA amongothers comprising a Policy Control Function, PCF, an ApplicationFunction, AF, and a Unified Data Repository, UDR.

The method according to the third aspect comprises the steps ofreceiving, by the UDR, from the PCF, an application rule applicable toan application to be accessed by the UE, the received application rulebeing different from existing Policy Charging and Control, PCC, rulesand having higher precedence than existing per session PCC rules,storing, by the UDR, the received application rule, receiving, by theUDR, from the PCF, a request for an application rule applicable to auser session, the request identifying an application to be accessed bythe UE, and transmitting, by the UDR, to the PCF, the requestedapplication rule stored in the UDR.

In the case of a 5G based SBA domain, for example, for new user PDUsessions, the UE triggers PDU session establishment by means of sendinga PDU Session Establishment Request to an Access and Mobility ManagementFunction, AMF, of the SBA domain. The AMF selects an SMF and triggersNsmf PDU Session Create. Subsequently, the SMF triggers anNpcf_SMPolicyControl_Create Request message to retrieve SessionManagement, SM, policies for the user PDU session. The PCF triggers anNudr_DM_Query Request message to retrieve the policy data for this userPDU session. The UDR will answer with an Nudr_DM_Query Response messageincluding the Subscriber Policy Data. The UDR may also return theapplication data including the AF-ID, App-ID, and service requirement(s)such as QoS-reference, for example indicating better than default QoS,and chargingProfile, for example sponsored data, whereby the applicationtraffic is not charged to the end user but to the content providerinstead.

In a fourth aspect of the present disclosure, there is presented aPolicy Control Function, PCF, in a Service Based Architecture, SBA,domain in a core network of a telecommunications system, the SBA furthercomprising, among others, an Application Function, AF and a SessionManagement Function, SMF, the PCF being arranged to implement anapplication to be accessed by a User Equipment, UE, in a user session inthe SBA domain.

The PCF comprising receive equipment arranged for receiving anapplication rule comprising an AF Identifier, AF-ID, identifying therespective application rule, an Application Identifier, App-ID,identifying the application, and at least one service requirement forprocessing the application in the SBA domain, the application rule beingdifferent from existing Policy Charging and Control, PCC, rules andhaving higher precedence than existing per session PCC rules, andinstruct equipment arranged for instructing the SMF, to execute the atleast one service requirement to all present and future user sessionspertaining to the application.

According to an embodiment, the SBA domain comprises a Unified DataRepository, UDR, the PCF further comprises transmit equipment arrangedfor transmitting a received application rule to the UDR, for storing inthe UDR, and wherein the receive equipment is further arranged forreceiving, from the UDR, a message acknowledging the storage of theapplication data.

In an embodiment, the receive equipment is further arranged forreceiving, from the SMF, a request to retrieve application rules for aProtocol Data Unit, PDU, session, and the PCF further comprises retrieveequipment arranged for retrieving, from the UDR, stored applicationrules and application data for the PDU session, and provide equipmentarranged for providing the retrieved application rules to the SMF.

In a fifth aspect of the present disclosure, there is presented aSession Management Function, SMF, in a Service Based Architecture, SBA,domain in a core network of a telecommunications system, the SBA furthercomprising, among others, an Application Function, AF, a User PlaneFunction, UPF and a Policy Control Function, PCF, the SMF being arrangedto support the implementation of an application to be accessed by a UserEquipment, UE, in a user session in the SBA domain.

The SMF comprises receive equipment arranged for receiving aninstruction from the PCF, instructing the SMF to execute a desiredapplication rule to all present and future user sessions pertaining tothe application, the desired application rule being different fromexisting Policy Charging and Control, PCC, rules and having higherprecedence than existing per session PCC rules, identification equipmentarranged for identifying user sessions to which the desired applicationrule is applicable, and implement equipment arranged for implementingthe desired application rule to the identified user sessions.

It may be understood by the skilled person that when the PCF instructsSMF to execute at least one service requirement to all existing andfuture user sessions using that application, the service requirementmight be executed at SMF but in some cases it may be needed to beexecuted at UPF. For example, QoS Bandwidth limitation is a servicerequirement that SMF cannot perform itself, and hence the SMF may needto instruct UPF to do so through a new N4 procedure, per application.Therefore, in such situations, where the application rule is directlynot executable at the SMF, but rather at the UPF or any other node, theimplement equipment may further be arranged to transmit said applicationrule to the UPF or any other node in order to implement the applicationrule.

In a sixth aspect of the present disclosure, there is presented aUnified Data Repository, UDR, in a Service Based Architecture, SBA,domain in a core network of a telecommunications system, the SBA furthercomprising, among others, a Policy Control Function, PCF, an ApplicationFunction, AF and a Session Management Function, SMF, the UDR beingarranged to support the implementation of an application rule for anapplication to be accessed by a User Equipment, UE, in thetelecommunications system.

The UDR comprising receive equipment arranged for receiving, from thePCF, an application rule applicable to an application to be accessed bythe UE, the application rule being different from existing PolicyCharging and Control, PCC, rules and having higher precedence thanexisting per session PCC rules, storage equipment arranged for storingthe received application rule. The receive equipment being furtherarranged for receiving, from the PCF, a request for an application ruleapplicable to a user session, the request identifying an application tobe accessed by the UE, and transmit equipment arranged for transmitting,to the PCF, the requested application rule stored in the storageequipment of the UDR.

In a seventh aspect of the present disclosure, a computer programproduct is provided, comprising a computer readable storage medium,storing instructions which, when executed on at least one processoroperative in an SBA domain, cause the at least one processor to carryout processing steps for performing the services according to arespective one of the first, second and third aspect of the presentdisclosure.

It will be appreciated that the entities and modules disclosed may beimplemented as separate hardware and/or software modules and entities,and controlled by or executed in a processor or the like.

The above mentioned and other features and advantages of the disclosurewill be best understood from the following description referring to theattached drawings. In the drawings, like reference numerals denoteidentical parts or parts performing an identical or comparable functionor operation.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 schematically illustrates a part of a reference architecture of aFifth generation, 5G, telecommunication systems according to the priorart.

FIG. 2 schematically illustrates a method according to the presentdisclosure.

FIG. 3 schematically illustrates a Policy Control Function, PCF, nodeaccording to the present disclosure.

FIG. 4 schematically illustrates a Session Management Function, SMF,node according to the present disclosure.

FIG. 5 schematically illustrates a Unified Data Repository, UDR,according to the present disclosure.

DETAILED DESCRIPTION

Embodiments contemplated by the present disclosure will now be describedmore in detail with reference to the accompanying drawings. Otherembodiments, however, are contained within the scope of the subjectmatter disclosed herein. The disclosed subject matter should not beconstrued as limited to only the embodiments set forth herein. Rather,the illustrated embodiments are provided by way of example to convey thescope of the subject matter to those skilled in the art.

FIG. 1 schematically illustrates part of a known reference architecture1 of a fifth generation, 5G, Service Based Architecture, SBA,telecommunication network. The 5G system architecture comprise thefollowing Network Functions, NFs:

-   -   Access and Mobility Management Function, AMF, 8    -   Network Exposure Function, NEF, 3    -   Policy Control Function, PCF, 6    -   Session Management Function, SMF, 9    -   Unified Data Repository, UDR, 2    -   User Plane Function, UPF, 10    -   Application Function, AF, 5    -   Network Data Analytics Function, NWDAF, 4    -   Charging Function, CHF, 7.

A functional description of these network functions is specified inclause 6 of the Third Generation Partnership Project, 3GPP, standard23.501, “System Architecture for the 5G system”, the contents of whichare included herein by reference.

The proposed solution allows a content provider (or network operator) toexecute a specific service requirement or service requirements, such asa particular Quality of Service, QoS, and/or charging handling, forexample, on a per application basis by implementing and executing anapplication rule.

The sequence diagram shown in FIG. 2 illustrates the case where acontent provider, for example a social media application contentprovider, requests to apply a better than default QoS for data exchangedin the SBA telecommunications system and/or a specific charging handlingto data exchanged with the respective social media application.

In a first step, the content provider applies 61 for a better thandefault QoS and/or a certain charging handling for the targetapplication, by triggering a new procedure in the Northbound ApplicationProgramming Interface, API, towards the network operator's NEF 3. It isproposed to define a new API—“Procedure for AF 5, to request a specificQoS and/or charging handling for an application” in the Third GenerationPartnership Project, 3GPP, Technical Specification, TS, 29.522 asdescribed below.

The content provider, through AF 5, sends 62 an HTTP POST message to theNEF 3. The body of HTTP POST message shall include an AF Identifier,AF-ID, identifying the application rule, an external App-ID, identifyingthe particular application, in this example a social media application,a QoS-reference, indicating a better than default QoS, and a chargingprofile, such as sponsored data, whereby the application traffic is notcharged to the end user but to the content provider instead. The skilledperson appreciates that the cited services are merely exemplary and maybe modified suitably to suit the needs of the consumer.

After receiving the message in Step 62, the NEF 3 shall authorize therequest, map the external App-ID to an (internal) App-ID and respondback 63 to AF 5 with a Nnef 200 OK successful response in this case. TheNEF 3 shall interact 64 with the PCF through Npcf by sending theparameters indicated above, namely AF-ID, App-ID, QoS-reference,charging profile. In FIG. 2 , for simplicity, a single PCF 6 instance isshown, but NEF 3 would need to trigger the procedure towards any PCF 6instance in operator's network.

After receiving the message in step 64, PCF 6 shall respond back 65 toNEF 3 with an Npcf 200 OK successful response and transmits 66 theparameters of the application rule to the UDR 2 in order to store 67 theapplication rule in the UDR 2 as “Application Data”, i.e. the parametersmentioned above AF-ID, App-ID, QoS-Reference and charging profile. Aspart of the Fifth generation, 5G, data storage architecture, UDR 2stores as “Application Data” the Packet Flow Descriptions, PFDs. In thepresent disclosure it is proposed to extend the “Application Data” toinclude service requirements, such as QoS and charging information on aper application basis. After storing 67 the “Application Data”, the UDR2 shall respond back 68 to PCF 6 with an Nudr 200 OK successfulresponse.

The PCF 6 shall install application rules by means of triggering an NsmfHTTP POST message 69 to the SMF 9 including, in the present example,AF-ID, App-ID, QoS-Reference and charging Profile. It may be noted thatthese application rules are different to the existing Policy Chargingand Control, PCC, rules as the application rules do not apply to aspecific user session, but instead they apply to any existing (andfuture) user session. Additionally, a precedence parameter may beconveyed in the application rule, but in the present disclosure forsimplicity we will assume the application rules have higher precedencethan the existing per user session PCC rules.

Alternatively, PCF 6 could identify all the existing user sessions whichwould require QoS modification and/or a different charging handling andtrigger a PCC rule modification on a per user session basis, but thiswould result in a lot of messages to be exchanged in thetelecommunications system, which would increase signalling. In FIG. 2 ,for simplicity, a single SMF instance 9 is shown, but the PCF 6 wouldneed to trigger the procedure towards any SMF instance 9 in operator'snetwork.

In a further step, SMF 9 identifies 70 the active user sessions whichrequire QoS modification and/or a new charging handling and applies thenew QoS and/or charging handling for each of them. Due to the Controland User Plane Separation, CUPS, feature, the Policy and ChargingEnforcement Function, PCEF, QoS and charging functionality is split intocontrol plane and user plane. This means that in this step 70, SMF 9would need to apply only the control plane part of the QoS and/orcharging. Two examples:

-   -   If the “application rule” consists of App-ID=social media        application and QoS-Reference=bandwidth limitation to x kbps,        this should be enforced by UPF 10, not impacting SMF 9.    -   If the “application rule” consists of App-ID=social media        application and charging profile=sponsored data, this should be        enforced by both SMF 9 and UPF 10, as follows:    -   SMF 9 would need to trigger a Call Detail Record, CDR, assuming        offline charging for the social media application indicating        that the charged entity is not the end user, but the content        provider itself.    -   UPF 10 would need to be instructed to report the volume for the        social media application.

In the step 71, the SMF 9 shall respond back to PCF 6 with an Nsmf 200OK successful response. The SMF 9 shall trigger 72 a (new) per nodePacket Forwarding Control Protocol, PFCP, procedure, for example a PFCPApplication Rule Request, to indicate to the UPF 10 the requested QoSand/or charging handling for the application. These application rulesare different to the existing PFCP rules which are based on PacketDetection Rule, PDR (PDI=App-ID), QoS Enforcement Rule, QER, and UsageReporting Rule, URR, as they do not apply to a specific user session,but instead they apply to any existing (and future) user session.Additionally, a precedence parameter may be conveyed, but in the presentdisclosure for simplicity it is assumed that the application rules havehigher precedence than the existing per user session PFCP rules.

In FIG. 2 , for simplicity, a single UPF 10 is shown, but SMF 9 wouldneed to trigger the procedure towards any UPF 10 handled by the SMF 9.The UPF 10 identifies 73 the active user sessions which require QoSmodification and/or a new charging handling and applies the new QoSand/or charging handling for each of them. As mentioned in Step 70above, due to the CUPS feature, the PCEF QoS and charging functionalityis split into control plane and user plane. This means that in this step73, UPF 10 would need to apply only the user plane part of the QoSand/or charging. UPF 10 shall respond back 74 to SMF 9 with a PFCPApplication Rule Response.

Steps 61-74 describe the mechanism to be applied to any existing userPDU sessions. The steps 75-84 define the mechanism to be applied for newor future user PDU sessions, for executing a particular application rulein accordance with the present disclosure.

User equipment, UE 11 triggers 75 a PDU session establishment, by meansof sending a PDU Session Establishment Request to AMF 8. AMF 8 selectsSMF 9 and triggers 76 Nsmf PDU Session Create. It may be noted that thesequence diagram in FIG. 2 does not include all the signalling messagesinvolved in the PDU Session Establishment procedure. These steps areknown to the person skilled in the art. Only the relevant signallingmessages for the present disclosure are described in subsequent steps.

In a step 77, the SMF 9 triggers an Npcf_SMPolicyControl_Create Requestmessage to retrieve Session Management, SM, policies for the user PDUsession. The PCF 6 triggers 78 Nudr_DM_Query Request message to retrievethe policy data for this user PDU session. The UDR 2 answers 79 withNudr_DM_Query Response message including the Subscriber Policy Data. Aspart of the present disclosure, UDR 2 will also return the ApplicationData including the AF-ID, App-ID, QoS-Reference, for example indicatinga better than default QoS, and charging profile such as sponsored data.

The PCF 6 generates 80 the corresponding PCC rules based on bothSubscriber Policy Data and Application Data. As mentioned, theprecedence parameter, if used, may determine which rules have to beapplied in case of conflict (i.e. either the ones in Subscriber PolicyData or the ones in Application Data), but in the example sequencediagram of FIG. 2 , for simplicity, it is assumed that the ApplicationData rules have higher precedence than the existing Subscriber PolicyData rules.

Based on the above generated PCC rules in step 80, the PCF 6 triggers 81Npcf_SMPolicyControl_Create Request message including the PCC rules tobe applied for this user PDU session. In this case, there will be a PCCrule for the social media application with a QoS-Reference (e.g.indicating better than default QoS) and with a charging profile (e.g.including the sponsor identity to indicate that this is sponsored data).

In a further step 82, SMF 9 selects UPF 10 and triggers a PFCP SessionEstablishment Request message including the correspondingPDRs/FARs/QERs/URRs. In this case, there will be a PDR with PDI of typeapplication with App-ID=social media application, a QER including theQoS-Reference, and a URR for reporting according to the chargingprofile, which indicates that the social media application should runwith a better than default QoS and report according to the conditions inthe charging profile.

UPF 10 stores the PDRs/FARs/QERs/URRs and answers back 83 to SMF 9 witha PFCP Session Establishment Response message. When a user opens therespective social media application, UPF 10 detects social mediaapplication traffic by matching the incoming packets with the PDR withPDI of type application with App-ID=social media application, applies 84the QoS in the QER mapped to this PDR, resulting in social mediaapplication traffic having better QoS than default user traffic. It willalso report based on the URR according to the charging profile.

Finally, it may be understood that the solution described in the presentdisclosure does not only apply to 5G network architecture, but the samemechanisms may also be applied to Fourth Generation, 4G,telecommunication network just by replacing:

-   -   NEF 3 by Service Capability Exposure Function, SCEF,    -   AF 5 by Services Capability Server/Application Server SCS/AS,    -   PCF 6 by Policy and Charging Rules Function, PCRF,    -   SMF 9 by PDN Gateway Control Plane Function, PGW-C, or Traffic        Detection Function-Control plane Function, TDF-C,    -   UPF 10 by PDN Gateway User Plane Function, PGW-U, or Traffic        Detection Function-User plane Function TDF-U.

FIG. 3 schematically illustrates a Policy Control Function, PCF, 6 nodeaccording to the present disclosure. The receive equipment 101, 102 isarranged for receiving an application rule comprising an AF Identifier,AF-ID, identifying the respective application rule, an ApplicationIdentifier, App-ID, identifying the application, and at least oneservice requirement for processing the application in the SBA domain.The instruct equipment 105 is arranged for instructing the SMF 9 toexecute the at least one service requirement to all present and futureuser sessions pertaining to the respective application. Such aninstruction may be transmitted to the SMF via the transmit equipment103, 104.

The transmit equipment 103, 104 may further be arranged for transmittingthe received application rule to the UDR 2, for storing in the UDR 2 asapplication data. Furthermore, the receive equipment 101, 102 is furtherarranged for receiving, from the UDR, a message acknowledging thestorage of the application data.

The receive equipment 101, 102 may further be arranged for receiving,from the SMF 9, a request to retrieve application rules for a ProtocolData Unit, PDU, session, and the PCF 6 further comprises retrieveequipment 106 arranged for retrieving, from the UDR 2, storedapplication rules and application data for the PDU session, andcomprises provide equipment 107 arranged for providing the retrievedapplication rules to the SMF 9. The PCF 6 further comprises a processor108 that is arranged for executing computer readable instructions storedin the memory 109. The internal modules communicate with one another viaa communication bus 110.

FIG. 4 schematically illustrates a Session Management Function, SMF, 9node according to the present disclosure. The SMF 9 comprises receiveequipment 151, 152 arranged for receiving an instruction from the PCF 6,instructing to execute a desired application rule to all present andfuture user sessions pertaining to a respective application. The SMF 9also comprises identification equipment 155 arranged for identifyinguser sessions to which the desired application rule is applicable.

The SMF 9 further comprises implement equipment 156 arranged forimplementing the desired application rule to the identified usersessions. The SMF node 9 may also communicate with other nodes in theSBA domain using the receive equipment 151, 152 and the transmitequipment 153, 154. The SMF 9 comprises a processor 157 that is arrangedfor executing computer readable instructions stored in the memory 158.The internal modules communicate with one another via a communicationbus 159.

FIG. 5 schematically illustrates a Unified Data Repository, UDR, 2according to the present disclosure. The UDR 2 comprises receiveequipment 201, 202 arranged for receiving, from the PCF 6, anapplication rule applicable to an application to be accessed by the UE.The UDR 2 further comprises storage equipment 205 arranged for storing,the received application rule.

The receive equipment 201, 202 is further arranged for receiving, fromthe PCF 6, a request for an application rule applicable to a usersession, the request identifying an application to be accessed by theUE, and transmit equipment 203, 204 arranged for transmitting, to thePCF, the requested application rule stored in the storage equipment 205of the UDR 2. The UDR 2 further comprises a processor 206 that isarranged for executing computer readable instructions stored in thememory 207. The internal modules communicate with one another via acommunication bus 208.

Other variations to the disclosed examples can be understood andeffected by those skilled in the art in practicing the presentdisclosure, form a study of the drawings, the disclosure and theappended claims. In the claims, the word “comprising” does not excludeother elements or steps and the indefinite article “a” or “an” does notexclude a plurality. A single processor or other unit may fulfil thefunctions of several items recited in the claims. The mere fact thatcertain measures are recited in mutually different dependent claims doesnot indicate that a combination of these measures cannot be used toadvantage. A computer program may be stored/distributed on a suitablemedium supplied together with or as part of other hardware, but may alsobe distributed in other forms, such as via the internet or other wiredor wireless telecommunication systems. Any reference signs in the claimsshould not be construed as limiting the scope thereof. Similar referencesigns denote similar or equivalent functionality.

The present disclosure is not limited to the examples as disclosedabove, and can be modified and enhanced by those skilled in the artbeyond the scope of the present disclosure as disclosed in the appendedclaims without having to apply inventive skills and for use in any datacommunication, data exchange and data processing environment, forexample for operational message handling between an SBA domain and fixednetwork access and Long Term Evolution, LTE, network access.

1. A method of supporting execution of an application rule for an application to be accessed by a User Equipment, UE, in a user session in a Service Based Architecture, SBA, domain in a core network of a telecommunications system, said SBA at least comprising a Policy Control Function, PCF, an Application Function, AF, a User Plane Function, UPF and a Session Management Function, SMF, said method comprising the steps of: receiving, by said SMF, an instruction from said PCF, instructing said SMF to execute a desired application rule to all present and future user sessions pertaining to said application, said desired application rule being different from existing Policy Charging and Control, PCC, rules and having higher precedence than existing per session PCC rules; identifying, by said SMF, user sessions pertaining to said application to which said desired application rule is applicable, and executing, by said SMF, said desired application rule to said identified user sessions pertaining to said application.
 2. The method according to claim 1, wherein said instruction comprises an AF Identifier, AF-ID an Application Identifier, App-ID, and at least one service requirement for processing said application in said SBA domain, wherein said identified user sessions are identified on the basis of said AF-ID and said App-ID.
 3. A method of supporting execution of an application rule for an application to be accessed by a User Equipment, UE, in a user session in a Service Based Architecture, SBA, domain in a core network of a telecommunications system, said SBA at least comprising a Policy Control Function, PCF, an Application Function, AF, and a Unified Data Repository, UDR, said method comprising the steps of: receiving, by said UDR, from said PCF, an application rule applicable to an application to be accessed by said UE, said received application rule being different from existing Policy Charging and Control, PCC, rules and having higher precedence than existing per session PCC rules; storing, by said UDR, said received application rule; receiving, by said UDR, from said PCF, a request for said application rule applicable to said user session, said request identifying an application to be accessed by said UE, and transmitting, by said UDR, to said PCF, said requested application rule stored in said UDR.
 4. A Session Management Function, SMF, in a Service Based Architecture, SBA, domain in a core network of a telecommunications system, said SBA at least comprising an Application Function, AF, a User Plane Function and a Policy Control Function, PCF, said SMF being arranged to support implementation of an application rule for an application to be accessed by a User Equipment, UE, in a user session in said SBA domain, said SMF comprising: receive equipment, arranged for receiving an instruction from said PCF, instructing to execute a desired application rule to all present and future user sessions pertaining to said application, said desired application rule being different from existing Policy Charging and Control, PCC, rules and having higher precedence than existing per session PCC rules; identification equipment, arranged for identifying user sessions pertaining to said application to which said desired application rule is applicable, and implement equipment, arranged for implementing said desired application rule to said identified user sessions pertaining to said application.
 5. The SMF according to claim 4, wherein said instruction comprises an AF Identifier, AF-ID an Application Identifier, App-ID, and at least one service requirement for processing said application in said SBA domain, wherein said identified user sessions are identified on the basis of said AF-ID and said App-ID.
 6. A Unified Data Repository, UDR, in a Service Based Architecture, SBA, domain in a core network of a telecommunications system, said SBA comprising a Policy Control Function, PCF, an Application Function, AF and a Session Management Function, SMF, said UDR being arranged to support implementation of an application rule for an application to be accessed by a User Equipment, UE, in a user session in said SBA domain, said UDR comprising: receive equipment, arranged for receiving, from said PCF, said application rule applicable to said application to be accessed by said UE, said application rule being different from existing Policy Charging and Control, PCC, rules and having higher precedence than existing per session PCC rules; storage equipment, arranged for storing, said received application rule; said receive equipment being further arranged for receiving, from said PCF, a request for an application rule applicable to a user session, said request identifying an application to be accessed by said UE, and transmit equipment arranged for transmitting, to said PCF, said requested application rule stored in said storage equipment of said UDR. 